checking if a number is int

[Jim Dennis]

In article <MPG.17197f04a3f463e8989680 at news.planet.nl>, Johannes Gijsbers wrote:

>logistix wrote:
>> Use python's type system:

>> >>> import types
>> >>> a, b = 1, 1.0
>> >>> if type(a) == types.IntType: print "int"
>> ...
>> int
>> >>> if type(b) == types.IntType: print "int"
>> ...
>> >>>

>That's not really a good idea, as math.sqrt() returns a float. I'd say:
 ...
>Johannes Gijsbers

 Worse, it doesn't account for subclasses of integer.

 In Python it is considered poor form to check for types;  it's 
 better to test for attributes or properties.  So one might
 take an anonymous object and do something like:

	def deal_with_unknown(a)
		if hasattr(a,'__mod__') and not a % 1:
			....

 ... since we can reasonably assert that all subclasses of numbers
 and integers should have (or inherit) an __mod__ (modulo) attribute.
 This example should short circuit so that any non-number that's
 passed to it will not raise an exception because a % 1 will be
 skipped if hasattr() is false.